These tables are historical listings of state senators who served in the South Dakota Senate from statehood in 1889 until the present.
+ Key to party colors for the South Dakota SenateDemocraticFusionIndependentNon-PartisanPopulistRepublican
Members of the South Dakota State Senate (1889–1939) 45 senators elected from 41 districts. Senators were elected from single-member districts, with five counties each electing two at-large senators. The number of senators was reduced to 43 senators from 1893 to 1899. A 42nd District was added in 1909.
+Multi-member at-large districts District Seats Years County 9th 2 1889–1909Minnehaha 10th 2 1909–1939 30th 2 1889–1893 Spink 32nd 2 1899–1909 Day 33rd 2 1909–1939Brown 35th 2 1909–1939 38th 2 1889–1893; 1899–1909Lawrence 39th 2 1909–1939